Who Was Edwin Hubble?

QUICK ANSWER

Edwin Hubble (1889-1953) was an American astronomer who made two of the most important discoveries in cosmology: that galaxies exist beyond our Milky Way, and that the universe is expanding. Often called the father of observational cosmology, he has NASA's Hubble Space Telescope named in his honor.

Edwin Hubble's discoveries changed the size of the known universe by orders of magnitude. Before him, many astronomers thought the Milky Way was the entire universe. Hubble showed it was just one of many galaxies and that the whole universe was expanding. His work made him one of the most important astronomers of the 20th century, and his namesake telescope continues his legacy in orbit today.

Who was Edwin Hubble?

An American astronomer born in 1889 in Marshfield, Missouri. According to NASA, Hubble was tall and athletic, even coaching high school basketball briefly. He studied mathematics and astronomy at the University of Chicago, then law at Oxford on a Rhodes Scholarship. He briefly practiced law before returning to astronomy. He joined Mount Wilson Observatory in California after serving in World War I, gaining access to what was then the world's largest telescope, the 100-inch Hooker telescope. He spent the rest of his career there.

What did he discover?

Two paradigm-shifting things. First, in 1924, he showed that what astronomers called the Andromeda Nebula was actually a separate galaxy beyond the Milky Way, settling a famous debate about whether the universe extended beyond our galaxy. Second, in 1929 he found that galaxies were moving away from us at speeds proportional to their distance: the farther away, the faster they recede. This relationship, now called Hubble's Law, was the first evidence that the universe is expanding. The discovery transformed cosmology.

How did he change astronomy?

He showed the universe is vastly larger than anyone had imagined, and that it has a history. Before Hubble, many astronomers thought the Milky Way was the whole universe. After Hubble, the universe contained countless galaxies stretching across billions of light years. His discovery that the universe is expanding implied a beginning, which eventually led to the Big Bang theory. He's often called the father of observational cosmology. Hubble's classification system for galaxies (spiral, elliptical, irregular) is still in use today.

What's his legacy?

Including the Hubble Space Telescope, launched in 1990 and named in his honor. The telescope has produced some of the most iconic images in science and made many landmark discoveries, continuing Hubble's tradition of expanding our understanding of the universe. The Hubble constant, which measures the rate of cosmic expansion, also bears his name. The Hubble Space Telescope helped show that cosmic expansion is actually accelerating, a discovery that Hubble himself wouldn't have predicted but that built directly on his work.

Edwin Hubble was the American astronomer who showed galaxies exist beyond the Milky Way and that the universe is expanding. His discoveries transformed cosmology from a relatively small field into one studying the largest structures in existence. NASA's Hubble Space Telescope, named in his honor, continues his work by mapping the universe and refining our understanding of cosmic expansion. He's one of the most important astronomers in history.

Who Was Edwin Hubble?